<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>todolist</title>
	<style type="text/css">
		.list_con{
			width:400px;
			margin:50px auto 0;
		}

		.inputtxt{
			width:350px;
			height:30px;
			border:1px solid #ccc;
			padding:0px;
			text-indent:10px;
			
		}

		.inputbtn{
			width:40px;
			height:32px;
			padding:0px;
			border:1px solid #ccc;
		}

		.list{
			margin:0;
			padding:0;
			list-style:none;
			margin-top:20px;
		}

		.list li{
			height:30px;
			line-height:30px;
			border-bottom:1px solid #ccc;
		}

		.list li span{
			float:left;
		}

		.list li a{
			float:right;
			text-decoration:none;
			margin:0 10px;
		}
	</style>
	<script type="text/javascript" src="js/jquery-1.12.4.min.js"></script>
	<script type="text/javascript">
		$(function(){

			$('#btn1').click(function(){

				var txt = $('#txt1').val();
				$('#txt1').val('');

				if(txt==''){
					alert('请输入内容！');
					return;
				}


				$li = $('<li><span>'+ txt +'</span><a href="javascript:;" class="up"> ↑ </a><a href="javascript:;" class="down"> ↓ </a><a href="javascript:;" class="del">删除</a></li>');

				$li.appendTo('#list');

			});



			/*

			$('.del').click(function() {
				$(this).parent().remove();
			});

			*/


			$('#list').delegate('a', 'click', function() {

				var handler = $(this).attr('class');

				if(handler=='del'){
					$(this).parent().remove();
				}

				if(handler=='up'){

					if($(this).parent().prev().length==0)
					{
						alert('到顶了！');
						return;
					}

					$(this).parent().insertBefore($(this).parent().prev());				
				}

				if(handler=='down'){

					if($(this).parent().next().length==0)
					{
						alert('到底了！');
						return;
					}

					$(this).parent().insertAfter($(this).parent().next());				
				}


			});



		})

	</script>	
</head>
<body>

	<div class="list_con">
	<h2>To do list</h2>
		<input type="text" name="" id="txt1" class="inputtxt">
		<input type="button" name="" value="增加" id="btn1" class="inputbtn">
		
		<ul id="list" class="list">

			<li><span>学习html</span><a href="javascript:;" class="up"> ↑ </a><a href="javascript:;" class="down"> ↓ </a><a href="javascript:;" class="del">删除</a></li>
			<li><span>学习css</span><a href="javascript:;" class="up"> ↑ </a><a href="javascript:;" class="down"> ↓ </a><a href="javascript:;" class="del">删除</a></li>
			<li><span>学习javascript</span><a href="javascript:;" class="up"> ↑ </a><a href="javascript:;" class="down"> ↓ </a><a href="javascript:;" class="del">删除</a></li>

		</ul>

	</div>
</body>
</html>